Now you understand why these buggers are causing me to completely re-evaluate my entire rig (actually, rigs) and my headphone collection!
I’ve gone a far as thinking that if I wind up with amps other than the two Vidar’s for my primary rig, maybe I just put these into other rigs and … put SR1as with them too! (See above picture …)
Oh, I checked and … “kids.eBay.com” isn’t what I thought it was … sorry!
Have you had a chance to listen to the SR1a’s with a more analog source? Say from your nice device for rotating vinyl? Or perhaps something in the 15 IPS tape range?
I’ve run them from my “baby” table (latest version of the Rega 3 Planar / Exact II, Neo TT PSU, w/ Groovetracer Reference Platter & Bearing, Rega Reference Belt, via a Park’s Audio Puffin) and that was quite lovely, and extremely revealing.
Sort of kills my interest in doing more needledrops … and instead maybe I’ll just buy the digital version at the same time as the LP, and listen to the LP when I can and the digital copy when I can’t …
I don’t have an R2R tape deck, but, oddly enough, this week I’ve been talking with Dan Schmalle (“Doc B.” of Bottlehead and “The Tape Project”, about commissioning a customized build of his (amazing) “Neothoriator” tube amp. So there’s a good chance that, in the near future, I’ll get to run not only the SR1a, but also the MySphere 3.x and AKG K1000 (their respective spiritual predecessors) against one of his amazing tape setups.
I’m very familiar with that modality.
This is madness! I’m on the same boat as @TylersEclectic, rethinking life choices and working hard to “convince” the missus that I need the SR1a + Vidar combo in my life. If I get this combo, I think I’m going to have to quit the hobby altogether and unsubscribe myself from audio forums before I get to read @Torq’s impressions of MySphere3.x!
I’ve been thinking about something, after looking at pictures online, how would you go about cleaning these as it appears the ribbons are open air? Just curious, maybe an IEM vacuum type device? Or that electronic goo stuff that is all the rage these days?
What? They’re not dishwasher safe?
So, today I became a sr1a owner. Of course I am typing this as hearing it 
A few initial impressions
Only if said appliance is a product of the “Albania State Dishwasher Company”.
Welcome to the club!
Looking forward to your impressions.
Some new listeners to my setup today … both seemed impressed. One didn’t feel the EQ (two-tier sub/bass lift) I prefer with them was necessary.
Definitely have to agree with these points.
I would consider the included cables as “get you started” and “guaranteed to meet spec” (cable assembly must be less than 0.2 ohms, which requires special equipment or techniques to measure reliably) affairs. It IS important to meet the impedance/capacitance requirements of the SR1a, so they’re a safe, if uninspired bet.
I’m running “costs more than the amps” speaker cables (because I can, not because there’s necessarily an audible benefit).
And I am definitely in the "give me locking mini 3 or 4 pin XLRs, HiRose (MrSpeakers) or LEMO (Utopia) connectors on the headphone end of things.
To that end, sometime in the next week or two I’ll have finished a custom cable offering for the SR1a. It’ll be ultra-low impedance and capacitance, shielded (with an active bias and active shield option). This will likely be followed by a “more upmarket” version of the SR1a interface box.
I should add …
“My” version of the “interface box” will use fundamentally the same implementation as the one from RAAL-requisite (in fact it’s internals will use original boards from the interface they sell … simply pulled from retail additional boxes), but with selectable treble emphasis and dual 3-pin XLRs (to allow the use of audiophile connectors/sockets while retaining the “can’t plug the wrong thing in” configuration).
Won’t be cheap.
Won’t necessarily sound any different.
Won’t be in anyway official, endorsed, sanctioned, nor approved by RAAL-requisite.
And I’ll make the details available if you want to build your own (at least for the non active-bias/active shield version) box … which anyone that could build it wouldn’t need anyway (but I digress).
Spam-posting again …
The SR1a make evaluating other headphones very hard.
Switching to pretty much any headphone, even the most resolving and quick options, after a protracted period of listening to the SR1a has a nasty habit of making everything sound “slower” and “veiled”.
These effects wear off after a few minutes, but they’re hard to ignore in the interim.
This might be the most vivid, and consistent, example of the “listen first, then go back to what you were listening to … to see the differences” vs. “do direct A/B/X comparisons” I’ve come across.
So, my Raal SR1a adventure started with an experiment of “How low can I (and sr1a) go?”.
$3.5k headphones connected to sub-$200 dac-pre (Topping DX3 Pro) and $100-ish seemingly underpower (10Wpc Class-A; referred to as JLH henceforth) integrated amp. You might think I am insane. Maybe I am…
But my insanity was calculated. I hypothesized SR1a could be effectively as sensitive as high-efficiency floor standers such as Tekton Lore I am using: 98 dbSPL per 1W and 1m.
Aside: 98 dbSPL at 1m = 92 dbSPL at 2m
Suppose full 10W goes to Lore speaker, then at 2m, sound pressure would be 102 dBSPL.
Now, what will happen 10W applies to SR1a?
10W at 8 Ohm equals to 8.94V and 1.12A
Suppose this 1.12A the maximum current – actually it can handle more but let’s assume conservatively 
SR1a impedance is claimed as 0.018 ohm excluding cable. So, power delivered to ribbon unit would be 0.0224W or 22.4 mW.
SR1a sensitivity is 85 dbSPL per mW. With 22.4mW, sound pressure will be 98.5 dbSPL (less than SR1a’s power handling of 111 dbSPL)
So 98.5 dbSPL for SR1a Vs. 102 dbSPL for Lore (at 2m). Hmm 
Aside: For Lore, I am using stereo configuration (left and right), also there will be some gain due to reflections. So a few decibel should be added to 102 dBSPL.
As shown, despite conservative assumption, SR1a is not that different from efficient speakers. So, logically, if the amp is fine with my Lore speaker (it actually is), then it must drive sr1a similarly.
Above is the technical conjecture. Did that work as thought?
I tested with low dynamic-range track – which is easier to feel ‘average’ loudness. Lady Gaga’s Bad Romance is one of my favorite testing tracks: -0.01 db peak, -6.7 db rms (root mean square; ‘on average’ in a layman’s term), DR5 according to EBU R128 loudness weighting.
I found myself happy enough with -22~-24 db of pre-gain during the whole track (including the loudest part), which correspond to 50-80 mW of amp’s power output. That’s within the ‘comfort zone’! (see below)
So at this point, my experience contradicts what Alex argues (100Wpc is a must) and I am starting to think it is not (rated) power that matters.
Do I mean higher amps unnecessary? Of course NOT.
I am hypothesizing that SR1a is revealing, resolving, and scaling enough to tell us what an amp can do and can’t. This headphone seems to tell me strengths (clear, neutral, and good staging) and weaknesses (rolled off low ends, mid-forwarding, micro-details not at the level of top performers) more evidently than my speakers and some of higher speakers I hooked up with before.
Tomorrow I am planning to test Vidar. Many (or nearly most) of shortcomings of JLH are technically addressed in modern amplifier designs (e.g., no capacitor in signal path), . For this reason, I am looking forward to a meaningful improvement in quality with Vidar (tomorrow) and Aegir (scheduled later this summer). What changed was that I was originally looking at only high powers but now considering sub-100W options as testing targets too.
PS. Check this out for in-depth technical details and explanations of JLH amp and its design. Very educational read. Highly recommended.
New peak …
Dual-mono Vidars … 124℉ (hottest point) … on about an hour of high-volume “New Order”.
I’m trying really hard not to buy these…I’ve just spent a small fortune on other toys recently…but damn they sound awesome!..
Also I don’t have a good space for the amps required to power them in my current space…
I need to come up with better reasons for not buying these… lol
The best way to do so is to unsubscribe this thread then ignore all Raalers (because they tend to use this as one reference point in every future comparison and evaluation!)
Trust me. A lesson from my own failure… 
Hi guys! I saw the post from SBAF and decided to come over and say hi. I was fortunate enough to receive one of the SR1a engineering samples as a review copy earlier in the year, and I’ve had a lot of time playing around with these and testing them with a variety of amps at different price points. Power delivery is indeed absolutely critical for the SR1a’s, being a current drive system at the headphone end. Bass on the SR1a’s is an extreme event for any power amp at critical listening volumes - power delivery will instantaneously go up from less than a watt to 20-30w or even more, and this is definitely not a load differential that amps are typically optimized for. You don’t have this problem with 2 channel because no 2 channel system will ever use ribbon drivers as woofers.
This is the main aspect that separate the boys from the men, so to speak. Most cheap amps - and some expensive ones - come up a bit short on bass texture and bass speed. You really want something extremely robust for driving them to get the best performance from the SR1a’s - something like a Bryston 14b3 is not out of the question as far as power is concerned! Bass isn’t going to be a major problem unless you’re driving it with a severely underpowered amp and run into clipping, but keep in mind that in most cases, the limiting factor to perceived speed is the amp, and not the headphones.
As I’ve mentioned on Headfi, single/dual Vidars are a very viable option for the SR1a’s, and I can enthusiastically recommend the 4b3 as a good higher-end option. Haven’t tried the Aegir, but I have put them on 200w pure Class A Lamm monoblocks, and that combination was absolutely incredible. Class A doesn’t mean that the amp isn’t subjected to the power requirement, but pure Class A amps typically have oversized power supplies relative to their output, which is good to have in the context of the SR1a.
Re: power requirement, “100w into 8 ohms” is the short version - the long version is that the box takes up to 150w into 6 ohms for a earpoint SPL of 111db when the flaps are fully closed onto your ears. That goes down to about 100-105db depending on how wide you open up the flaps and the position of the drivers relative to your ears. However, 110db is still an extremely high listening volume. I don’t even evaluate my gear at anything close to that, and some napkin math will show that if you only ever listen at volumes up to 100-ish db, you can get away with a 40-50w amp, or even lower if you’re okay with a tiny bit of bass clipping. I wouldn’t buy a 40w amp with the sole purpose of driving the SR1a’s, but if you have a weaker amp (say 20-25w on 845 tubes or 18-20w on quad 300b), it could be a reasonably good solution as long as you know the limitations.
Re: cables, lowering the resistance of the cable decreases treble response noticeably - you get around -1db at around 8k if you lower the cable to about 0.05 ohms. That may or may not be a good thing depending on your tastes. I tried them with a friend’s silver wire and the change was substantial, orders of magnitudes larger than swapping cables on other headphones. Ultimately I figured that I was happy enough with what the stock cable did and decided to not go for a cable swap for the time being. The stock cable for these is pretty decent stuff - the same solid-core wire that Danny uses for both his own IC’s and for wiring up studio setups.
Edit: cleared up a couple numbers.
Post spamming as the previous post is awaiting approval…One other thing, Alex is working on a direct current drive amp (think Bakoon) that will be able to drive the SR1a’s 0.2 ohm load without an adapter box and possibly even run on a battery pack, for field or on-site monitoring work. Nothing concrete yet, but something to look forward to in the future 
Thanks for the insight on amp options for the SR1a. Do you think that an Amp like the relatively cheap Emotiva BasX A-300 ($399 rated at 150Wpc into 8ohm and 300Wpc into 4ohm) can drive the SR1a properly without any major compromises? I’m looking at it as a cheaper alternative to the Vidar (maybe?)… @Torq I would also like to get your thoughts on this and check if the A300 would make it to your list of testing amps.
Thanks
